The gastrointestinal (“GI”) function is to process and consume food, to extract nutrients and to dispose of waste products of digestion. The digestive system is a twisted shaped tube that starts with the mouth, throat, gullet (esophagus), stomach, ileum (small intestine), colon (large intestine), rectum and anus. This muscular tube is some 25 feet long with most of it coiled within the abdomen. The stomach is a complex organ of the digestive tract (alimentary canal) with the primary functions of dissolution, reduction, and motility of ingested food. Normal contractions of the stomach are the result of three control components: neural activity, chemical activity, and myogenic activity. The neural control component refers to the intrinsic and extrinsic nerves innervating the stomach.
Direct electrical stimulation of the stomach and other portions of the gastric intestinal tract has been experimented with for some time. Most of the experimentation has been oriented toward improving the gastric emptying usually by attempting to speed up or strengthen/reinforce the peristaltic activity through directly placing stimulators on the muscles involved. For example, some of the work has centered on using direct electrical stimulation for the treatment of gastroparesis, or delayed stomach emptying, a condition that is most often a complication of diabetes. Seven million people in the United States may be affected by diabetes, and up to 75% of diabetic patients may experience gastrointestinal dysfunction, including diabetic gastroparesis, a syndrome of delayed gastric emptying, leading to nausea, vomiting, abdominal pain and early satiety.
U.S. Pat. No. 5,423,872 to Cigaina for “Process and Device for Treating Obesity and Syndromes Related to Motor Disorders of the Stomach of a Patient” issued Jun. 3, 1995, describes an implantable gastric electrical stimulator at the antrum area of the stomach which generates sequential electrical pulses to stimulate the entire stomach, thereby artificially altering the natural gastric motility to prevent emptying or slows down food transit through the stomach. U.S. Pat. No. 5,690,691 to Chen et al. for “Gastro-intestinal Pacemaker Having Phased Multi-Point Stimulation” issued Nov. 25, 1997, describes a portable or implantable gastric pacemaker employing a number of electrodes along the greater curvature of the stomach for delivering phased electrical stimulation at different locations to accelerate or attenuate peristaltic movement in the GI tract. U.S. Pat. No. 5,836,994 to Bourgeois for “Method and Apparatus for Electrical Stimulation of the Gastrointestinal Tract” issued Nov. 17, 1998, describes an implantable gastric stimulator which incorporates direct sensing of the intrinsic gastric electrical activity by one or more sensors of predetermined frequency bandwidth for application or cessation of stimulation based on the amount of sensed activity. U.S. Pat. No. 6,091,992 to Bourgeois for “Method and Apparatus for Electrical Stimulation of the Gastrointestinal Tract” issued Jul. 18, 2000 relates to provision of separate electrical pulse trains of differing parameters wherein the pulse trains are composed of a series of at least two pulses. The therapy is applied to promote gastric peristalsis.
U.S. Pat. No. 6,104,955 to Bourgeois for “Method and Apparatus for Electrical Stimulation of the Gastrointestinal Tract” issued Aug. 15, 2000, relates to a gastric stimulator with reversion to a sensing mode to determine the intrinsic slow wave interval to prevent stimulation when the gastric tract is in inter-digestive phases. U.S. Pat. No. 5,861,014 to Familoni for “Method and Apparatus for Sensing a Stimulating Gastrointestinal Tract On-Demand” issued Jan. 19, 1999, relates to an implantable gastric stimulator for sensing abnormal electrical activity of the gastrointestinal tract so as to provide electrical stimulation for a preset time period or for the duration of the abnormal electrical activity to treat gastric rhythm abnormalities.
Despite the attempts to modulate the gastrointestinal system via direct electrical stimulation, there are still several patients in which this type of stimulation system does not provide relief from their gastrointestinal and/or eating disorder. Thus, the present invention provides a novel method of using spinal cord stimulation to treat gastrointestinal and/or eating disorders or conditions.